Various technologies have been proposed to act as guides for visitors in an exhibition facility such as a gallery and a museum. For example, Patent Document 1 discloses an auto-reproducing voice guide system that utilizes transmission devices placed near exhibits in a gallery or a museum and portable receivers carried by visitors. A transmission device intermittently transmits an identification code unique to an exhibit to its surroundings by radio waves or infrared rays. A portable receiver reproduces, from among guide voices stored beforehand in its storage medium, a guide voice that corresponds to an identification code received from a transmission device. According to Patent Document 1, after a portable receiver moves within a range (around an exhibit) wherein radio waves or infrared rays from a transmission device reach the portable receiver and receives an identification code, a guide voice describing the exhibit within this range is reproduced.